Sealing ability of amalgam, super EBA cement, and MTA when used as retrograde filling materials

Premixed Calcium Silicate-Based Root Canal Sealer Reinforced with Bioactive Glass Nanoparticles to Improve Biological Properties

Recently, bioactive glass nanoparticles (BGns) have been acknowledged for their ability to promote interactions with the periapical tissue and enhance tissue regeneration by releasing therapeutic ions. However, there have been no studies on calcium silicate sealers with bioactive glass nanoparticle (BGn) additives. In the present study, a premixed calcium silicate root canal sealer reinforced with BGn (pre-mixed-RCS@BGn) was developed and its physicochemical features and biological effects were analyzed. Three specimens were in the trial: 0%, 0.5%, and 1% bioactive glass nanoparticles (BGns) were gradually added to the premixed type of calcium silicate-based sealer (pre-mixed-RCS). To elucidate the surface properties, scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy were used and flowability, setting time, solubility, and radiopacity were analyzed to evaluate the physical properties. Chemical properties were investigated by water contact angle, pH change, and ion release measurements. The antibacterial effects of the bioactive set sealers were tested with Enterococcus faecalis and the viability of human bone marrow-derived mesenchymal stem cells (hMSCs) with this biomaterial was examined. In addition, osteogenic differentiation was highly stimulated, which was confirmed by ALP (Alkaline phosphatase) activity and the ARS (Alizarin red S) staining of hMSCs. The pre-mixed-RCS@BGn satisfied the ISO standards for root canal sealers and maintained antimicrobial activity. Moreover, pre-mixed-RCS@BGn with more BGns turned out to have less cytotoxicity than pre-mixed-RCS without BGns while promoting osteogenic differentiation, mainly due to calcium and silicon ion release. Our results suggest that BGns enhance the biological properties of this calcium silicate-based sealer and that the newly introduced pre-mixed-RCS@BGn has the capability to be applied in dental procedures as a root canal sealer. Further studies focusing more on the biocompatibility of pre-mixed-RCS@BGn should be performed to investigate in vivo systems, including pulp tissue.

Cytotoxic Effect of Nano Fast Cement and ProRoot Mineral Trioxide Aggregate on L-929 Fibroblast Cells: an in vitro Study

Statement of the Problem:

Endodontic materials that are placed in direct contact with living tissues should be biocompatible. The cytotoxicity of Nano Fast Cement (NFC) compared to ProRoot Mineral Trioxide Aggregate (ProRoot MTA) must be evaluated.

Purpose:

This In vitro study aimed to assess the cytotoxic effects of NFC in comparison to ProRoot MTA on L-929 mouse fibroblast cells.

Materials and Method:

In this animal study, L-929 mouse fibroblast cells were grown in Dulbecco's Modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS) in an atmosphere of 5% co₂/95% air at 37 C̊. A total of 10⁴ cells from the fourth collection were plated in each well of a 96-well micro-titer plate. Materials were mixed according to the manufacturer’s instruction and placed into the related plastic molds with 5 mm diameter and 3 mm height. After 24 hours and a complete setting, the extracts of the tested materials were produced at six different concentrations and placed in the related wells. Cells in DMEM served as the negative control group. DMEM alone was used as the positive control group. Methyl-thiazoltetrazolium (MTT) colorimetric assay was conducted after 24, 48, and 72 hours. The absorbance values were measured by ELISA plate reader at 540 nm wavelength. Three-way analysis of variance, post-hoc Tukey, LSD, and independent t-test were used for the statistical analyses using SPSS software, version 16.0.

Results:

There was no statically significant difference between MTA and NFC in cell viability values at different concentrations and different time intervals (p= 0.649). Viability values were significantly decreased after 72 hours, but there was no significant difference between the first and second MTT assays (p= 0.987). Cytotoxicity significantly increased at concentrations higher than 6.25 µɡ/ml.

Conclusion:

Cytotoxicity depends on time, concentration, and cement composition. There was no statistically significant difference between NFC and MTA concerning their cytotoxic effects on L-929 mouse fibroblast cells.

Portland Cement: An Overview as a Root Repair Material

Portland cement (PC) is used in challenging endodontic situations in which preserving the health and functionality of pulp tissue is of considerable importance. PC forms the main component of mineral trioxide aggregate (MTA) and demonstrates similar desirable properties as an orthograde or retrograde filling material. PC is able to protect pulp against bacterial infiltration, induce reparative dentinogenesis, and form dentin bridge during the pulp healing process. The biocompatibility, bioactivity, and physical properties of PC have been investigated in vitro and in animal models, as well as in some limited clinical trials. This paper reviews Portland cement's structure and its characteristics and reaction in various environments and eventually accentuates the present concerns with this material. This bioactive endodontic cement has shown promising success rates compared to MTA; however, considerable modifications are required in order to improve its characteristics and expand its application scope as a root repair material. Hence, the extensive chemical modifications incorporated into PC composition to facilitate preparation and handling procedures are discussed. It is still important to further address the applicability, reliability, and cost-effectiveness of PC before transferring into day-to-day clinical practice.

Physicochemical Properties, Cytocompatibility, and Biocompatibility of a Bioactive Glass Based Retrograde Filling Material

The ideal retrograde filling material that is easy to handle, has good physicochemical properties, and is biocompatible has not yet been developed. The current study reports the development of a novel bioactive glass based powder for use as a retrograde filling material that is capable of altering the consistency and hardening rate of mixtures when mixed with existing bioactive glass based cement. Furthermore, its physicochemical properties, in vitro effects on human cementoblast-like cells, and in vivo effects on inflammatory responses were evaluated. The surface of the hardened cement showed the formation of hydroxyapatite-like precipitates and calcium and silicate ions were eluted from the cement when the pH level was stabilized at 10.5. Additionally, the cement was found to be insoluble and exhibited favorable handling properties. No adverse effects on viability, proliferation, and expression of differentiated markers were observed in the in vitro experiment, and the cement was capable of inducing calcium deposition in the cells. Moreover, the cement demonstrated a lower number of infiltrated inflammatory cells compared to the other materials used in the in vivo mouse subcutaneous implantation experiment. These findings suggest that the retrograde filling material composed of bioactive glass and the novel bioactive glass based powder exhibits favorable physicochemical properties, cytocompatibility, and biocompatibility.

Comparison of Obturation Quality after MTA Orthograde Filling with Various Obturation Techniques

This study aimed to quantify and compare the obturation quality after mineral trioxide aggregate (MTA) orthograde fillings with three different obturation techniques. Thirty-three extracted human maxillary molars were collected. Distobuccal and palatal canals were prepared to an apical size of #40/06 with a Profile Ni-Ti system. All 66 canals were divided into two groups according to the material (EZ-seal or OrthoMTA) and then obturated using three different techniques: manual compaction using S-kondenser (group H), compactor activation (group C), or reverse rotary motion of Ni-Ti file (group R). The obturated roots were scanned using micro-computed tomography (micro-CT). The percentage of voids located in the apical 5 mm was measured separately, that is, closed, open, and total porosity. There was no relation between the filling material and obturation technique (p > 0.05). The percentage volume of open and total porosity was higher in EZ-seal than in OrthoMTA (open: p = 0.002, total: p = 0.001). Group H showed higher open and total porosity than groups C and R. Micro-CT analysis showed that the void volume after orthograde MTA fillings significantly decreased when the additional activation was accompanied by hand condensation. Obturation with a Ni-Ti file using reverse motion could be recommended as an MTA orthograde filling technique.

Synthesis and characterization of novel calcium phosphate glass-derived cements for vital pulp therapy

Evaluation of the physicochemical behavior and setting reactions of a novel inorganic pulp capping cement which makes use of the unique corrosion properties of sodium metasilicate (NaSi) glass. NaSi and calcium phosphate (CaP) glass powders were synthesized through a melt-quench method. Cements were created by mixing various amounts of the glasses with deionized water at a powder-to-liquid ratio of 2.5 g mL^-1. Working and setting times were measured using the indentation standard ISO 9917-1. Sealing ability was tested by placing set samples of each composition in methylene blue dye solution for 24 h. Set samples were also submerged in phosphate buffered saline and incubated at 37 °C for one week. X-ray diffraction was used to identify mature crystalline phases after incubation. Infrared spectroscopy and scanning electron microscopy were used to characterize cements before and after setting and after incubation. Working and setting times measured in the ranges of 2-5 and 10-25 min, respectively. Working and setting time generally decrease with increased NaSi concentration. Cements with compositions of 25 and 33 wt% NaSi were found to resist the infiltration of dye and maintain their shape. Compositions outside this range absorbed dye and collapsed. Infrared spectroscopy provided insight into the setting mechanism of these cements. After one week in vitro, cements were found to contain crystalline phases matching chemically stable, bioactive phases. The combination of NaSi and CaP glasses has favorable setting behavior, sealing ability, and mature phases for pulp capping while relying on a relatively simple, inorganic composition.

Multidisciplinary Management and Pulp Vitality Preservation of a Tooth With Extensive Iatrogenic Furcal Root Perforation and Biologic Width Violation

This article describes the case of a vital molar tooth with a vast furcal iatrogenic root perforation and biologic width violation, which was successfully managed by a multidisciplinary approach aimed at preserving pulp vitality. The root perforation was cleaned and then sealed with mineral trioxide aggregate, which was positioned onto the pulp at the canal orifices. After one month, the patient was not reporting symptoms, and the tooth was positively responding to the thermal test. The tooth was orthodontically extruded, subjected to minimally invasive crown lengthening, and prepared to receive a full-crown restoration. Radiotransparent composite resin was chosen as a permanent restorative material to better monitor possible endodontic complications at the coronal level. The patient's tooth was followed up for eight years uneventfully. The present case is an example of the possibility to subject a root-repaired tooth with fully formed apices to conservative yet complex multidisciplinary treatment while maintaining pulp vitality.

Evaluation of Crack Formation and Propagation with Ultrasonic Root-End Preparation and Obturation Using a Digital Microscope and Optical Coherence Tomography

OBJECTIVE

This study is aimed at determining (1) the effect of root-end resection, ultrasonic root-end preparation, and root-end filling on the incidence of crack formation and propagation by using a digital microscope (DM) and optical coherence tomography (OCT) and (2) the performance of OCT on the detection of cracks by comparing with microcomputed tomography (micro-CT) as a reference standard.

METHODOLOGY

Thirty extracted lower incisors were endodontically treated and subjected to root-end resection and ultrasonic root-end cavity preparation. Then, the teeth were divided into three groups (n = 10, each), and the root-end cavity was either left unfilled or filled with mineral trioxide aggregate (MTA) or super-EBA. The resected surface was observed with OCT and DM after the root-end resection, ultrasonic root-end preparation, and root-end filling, and the frequency of incomplete and complete cracks were recorded. The observation was repeated after two weeks, one month, and two months, and micro-CT scans after two months were taken as the gold standard.

RESULTS

The DM results show dentinal crack formation in 47% of the samples following root-end resection and in 87% following ultrasonic preparation. After the ultrasonic preparation, no existing crack propagated to a complete crack, but new cracks were formed. MTA and super-EBA had no effect on crack formation. The Spearman correlation coefficient between OCT and DM was 0.186 (very weak correlation; p = 0.015). Sensitivity and specificity in comparison to micro-CT were 0.50 and 0.55 in OCT and 1.00 and 0.35 in DM, respectively. McNemar's test showed a significant difference between OCT and DM (p < 0.05).

CONCLUSION

Apical resection and ultrasonic preparation could form dentinal cracks. OCT and DM showed different detection frequencies of cracks with very weak correlation. DM showed superior sensitivity compared with OCT.

Solubility of Root Canal Sealers: A Comparative Study

Introduction

Root canal sealers used in odontological applications are capable of providing an apical seal, thus inhibiting potential bacterial penetration into the periradicular tissues. Since insolubility is the ideal characteristic for a root canal sealer material, in dentistry the sealability of the material depends on its solubility.

Purpose

This study tested the solubility of six different root canal sealers: two ZnOE-based sealers (Endomethasone C and Argoseal), two calcium hydroxide-containing sealers (Bioseal Normal and Acroseal), and two resin-based sealers (AH Plus and MM Seal).

Methods

Ten specimens of each material were prepared using stainless steel ring molds with the same internal diameter and the same height in order to obtain similar samples, and immersed in water. Solubility was determined by using sample weight loss (%) after 24 hours and after 2 months. The test was performed according to the International Standards Organization 6876 standard and the American Dental Association specifications No. 30 and No. 57. Data were statistically analyzed with a one-way analysis of variance test (ANOVA).

Results

The ANOVA test showed significant differences between the various groups. The post-hoc test showed that resin-based root canal sealers had significantly lower solubility percentages than other groups (p<0.05), and showed no difference between them (p>0.05).

Conclusions

All the materials fulfilled the requirements of International Standard 6876 and ANSI/ADA specifications demonstrating a weight loss of less than 3%. Under the conditions of the present study, all root canal sealers were of low solubility, but the lowest solubility percentages were recorded in resin-based root canal sealers, which can be considered virtually insoluble, and thanks to this physical property, ideal for use as endodontic sealer.

Current status of direct pulp-capping materials for permanent teeth

Direct pulp-capping is a method for treating exposed vital pulp with dental material to facilitate the formation of reparative dentin and to maintain vital pulp. Two types of pulp-capping materials, calcium hydroxide and mineral trioxide aggregate, have been most commonly used in clinics, and an adhesive resin has been considered a promising capping material. However, until now, there has been no comprehensive review of these materials. Therefore, in this paper, the composition, working mechanisms and clinical outcome of these types of pulp-capping materials are reviewed.

Biological response of commercially available different tricalcium silicate-based cements and pozzolan cement

This study evaluated four root repair materials for cytotoxicity and cell attachment in vitro. Cell viability was determined at 24 hr, 3 days and 7 days by using a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay with material extracts. Cell adhesion was examined with a scanning electron microscope on the surface of materials at 24 and 48 hr. Angelus MTA displayed the lowest cell viabilities at all-day incubations. Endocem had high biocompatibility on the first day. After culturing for 3 days and 7 days, the cell viabilities of Biodentine, Endocem and MM-MTA had similar results, and their cell viability was significantly higher than that of Angelus. No definite relation was found between the incubation time and the relative cell viability in any group. In scanning electron micrographs, the cells were attached to the material surface for all materials, although the cells in the Biodentine group were attached better than the other groups on the second day. Cell viability and cell attachment was lower in the Angelus group. Endocem, Biodentine and MM-MTA were similar in biocompatibility and cytotoxicity.

The sealing ability of novel Kryptonite adhesive bone cement as a retrograde filling material

Background. This study evaluated the ability of Kryptonite bone cement in sealing retrograde cavities. Methods. The root canals of one hundred extracted human maxillary incisor teeth were instrumented up to master apical file #40 using Mtwo rotary system and obturated with gutta-percha and AHPlus sealer by cold lateral compaction method. The specimens were assigned to one control group and four experimental groups based on the retrograde filling materials (n=20). The specimens were immersed in 0.5% Rhodamine B solution for 48h. Then the specimens were divided longitudinally into two parts and the depth of dye penetration was assessed under ×10 magnification. Data were analyzed using one-way ANOVA and Bonferroni tests. Results. There were statistically significant difference between the experimental groups and the control group (P<0.05). There were no statistically significant differences between the experimental groups in dye penetration scores (P>0.05). Conclusion . Kryptonite cement provided optimal apical seal in a manner similar to MTA, amalgam and IRM when used as a retrograde filling cement.

A Comparative Evaluation of Sealing Ability of New MTA Based Sealers with Conventional Resin Based Sealer: An In-vitro Study

INTRODUCTION

Root canal obturation is the most important step in the root canal treatment that aims to obtain a complete hermetic seal and to prevent the re-growth of microorganisms in the root canal system. To accomplish this, many endodontic obturation materials and sealers are being used.

AIM

To evaluate and compare the apical microleakage of a resin based sealer; Adseal with Mineral Trioxide Aggregate (MTA) based sealers; Pro root MTA and MTA Fillapex.

MATERIALS AND METHODS

Total 75 extracted human single rooted teeth were taken and decoronated at cemento-enamel junction. The access cavities and biomechanical preparation were performed using endodontic rotary system. The teeth were randomly divided into five groups with n=15; Group I - Gutta-percha and Adseal sealer; Group II - Gutta-percha and MTA Fillapex; Group III- Gutta-percha and Pro root MTA; Group IV- Gutta-percha without sealer (positive control group); Group V- Root canal remained empty (negative control). All the specimens were stored at 37(0)C with 100% humidity for one week. All root surfaces except the apical 2mm were covered with two layers of nail varnish and then immersed in an aqueous solution of 2% methylene blue dye for 72 hours. Roots were longitudinally split using a diamond disk. Linear apical dye penetration was measured under Stereomicroscope at 40X magnification.

STATISTICAL ANALYSIS

The data obtained was subjected to statistical analysis using paried t-test, ANOVA for interclass comparison, with SPSS statistical software (version 20.0).

RESULTS

The intraobserver reliability was found to be insignificant in each of the triplicate study of all the three study samples. MTA Fillapex group showed maxmium apical microleakage followed by Pro root MTA and Adseal sealer.

CONCLUSION

The results concluded that Adseal sealer showed minimal dye penetration followed by Pro root MTA and MTA Fillapex. Thus, concluding that Adseal sealer is better in apical sealing than Pro root MTA and MTA Fillapex.

Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study

OBJECTIVES

To compare the contrast-to-noise ratio (CNR) of multiple acquisition settings for four types of retrograde filling materials in CBCT images taken for endodontic surgery follow-up.

METHODS

20 maxillary central incisors were endodontically treated and obturated with 4 different root-end filling materials: amalgam, mineral trioxide aggregate, SuperEBA(™) (Harry J Bosworth Company, Skokie, IL) and Biodentine™ (Septodont, Saint-Maur-des-Faussés, France). Teeth were placed in a skull and scanned, one by one, with the Planmeca ProMax(®) 3D Max (Planmeca, Helsinki, Finland); at different voltages: 66, 76, 84 and 96 kVp; with low, normal and high resolution and high definition (HD); with and without metal artefact reduction (MAR). Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. The dose-area product was registered, and the effective dose calculated.

RESULTS

No statistically significant difference was noted between the four materials. 84 and 96 kVp with low resolution and the use of MAR-generated images that have statistically better CNR than 66 and 76 kVp with HD, normal and high resolutions and without MAR. The use of low resolution also generated the smallest value of effective dose.

CONCLUSIONS

The best setting for radiographic follow-up in an endodontic surgery with retrograde filling on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses.

Comparative evaluation of sealing ability and microstructure of MTA and Biodentine after exposure to different environments

OBJECTIVES

The aim of this study was to evaluate the sealing ability and morphological microstructure of Biodentine in comparison to ProRoot mineral trioxide aggregate (MTA) after storage in an acidic environment.

MATERIALS AND METHODS

Biodentine and ProRoot MTA were prepared and packed into the canal lumen of dentin disks. Twenty specimens of each material were further randomly divided into two groups according to the storage media: group A: materials with saline as storage medium; group B: materials with citric acid buffered at pH 5.4 as storage medium. The sealing ability was evaluated at 1, 3, 6, and 24 h and 1 or 3 months, using a fluid transport model for quantitative analysis of endodontic microleakage. The morphological microstructures of the materials were also evaluated using scanning electron microscopy.

RESULTS

During the first 24 h, MTA showed greater fluid transport values than Biodentine in both environments. At the 3-month measurement, when the materials were stored in saline, MTA showed greater ability to prevent fluid movement than Biodentine (p < 0.0001). However, when the materials were stored in an acidic environment, no statistical significant difference was found after 3 months. After storage in saline, both materials showed an uneven crystalline surface with similar hexagonal crystals. The microstructure of Biodentine changed after exposure to citric acid, showing a relatively smooth surface with more spheroidal crystals.

CONCLUSIONS

The exposure to an acidic environment, within the limits of this study, seems to result in morphological changes of Biodentine in a different manner than MTA. MTA shows good ability to prevent fluid movement over time, in both environments. The ability of Biodentine to prevent fluid movement over time was enhanced in the acidic environment.

CLINICAL RELEVANCE

The findings of the present study could imply that both materials are indicated for use in an acidic environment.

Solubility of a new calcium silicate-based root-end filling material

INTRODUCTION

The purpose of this study was to compare solubility of a new calcium silicate-based cement, Biodentine with three commonly used root-end filling materials viz. glass-ionomer cement (GIC), intermediate restorative material (IRM), and mineral trioxide aggregate (MTA).

MATERIALS AND METHODS

Twenty stainless steel ring molds were filled with cements corresponding to four groups (n = 5). The weight of 20 dried glass bottles was recorded. Samples were transferred to bottles containing 5 ml of distilled water and stored for 24 h. The bottles were dried at 105΀C and weighed. This procedure was repeated for 3, 10, 30, and 60 days. Data was analyzed with one-way analysis of variance (ANOVA) test (P < 0.05).

RESULTS

Biodentine demonstrated significantly higher solubility than MTA for 30- and 60-day immersion periods. Statistical difference was noted between the solubility values of Biodentine samples amongst each of the five time intervals.

CONCLUSIONS

Biodentine exhibited higher solubility in comparison with all other cements.

Microleakage evaluation around retrograde filling materials prepared using conventional and ultrasonic techniques

INTRODUCTION

The importance of the retrograde cavity preparation and the material used to restore is of utmost importance to achieve successful surgical endodontics.

AIM

The aim of the present study is to evaluate the apical micro-leakage of root end cavities filled with Mineral trioxide aggregate, Biodentine and light cure GIC using two different cavity preparation techniques that is conventional bur preparation and ultrasonic tip preparation.

MATERIALS AND METHODS

Eighty extracted single rooted human teeth (except mandibular incisors) with one canal, fully developed apices and without any major carious lesion are collected for the study. The teeth were sectioned at CEJ to standardize the length. Roots are instrumented upto master apical file 40 K size and obturated with gutta percha and AH plus sealer in lateral condensation technique. The teeth were then resected apically at 90° angle axis to the long axis of the root removing 3 mm of the apex. The teeth were divided in to four groups of 20 each- • Group I- samples restored with MTA. • Group II- samples restored with Biodentine. • Group III- (Positive control group)- samples restored with Light activated GIC. • Group IV - (negative control group)- no filling material. Each group is divided into two subgroups (a, b) of ten teeth each 1. Retropreparation done with ultrasonic retrotip. 2. Retropreparation done with conventional bur. The teeth were then immersed in 0.5% Rhodamine B dye for 48 h. The teeth were split longitudinally and the interface between the restored material and the canal wall is observed under Confocal laser scanning microscope. Depth of dye penetration was examined under stereomicroscope.

RESULTS

The statistical analysis was performed by One way ANOVA, t test. Pair wise comparision was done by Newman - Keuls multiple post hoc test. The mean values of Dye penetration for Group Ia (321.23), Group Ib (490.11), Group IIa (1065.14), Group IIb (1170.96), Group IIIa (1888.90), Group IIIb (2025.35). The samples prepared with ultrasonic retrotip showed less microleakage but it is statistically not significant.

CONCLUSION

MTA showed significantly less microleakage when compared to Biodentine and light cure GIC and there is no statistical difference between the ultrasonic retrotip preparation and conventional bur preparation.

Temperature Profiles Along the Root with Gutta-percha Warmed through Different Heat Sources

OBJECTIVES

To evaluate temperature profiles developing in the root during warm compaction of gutta-percha with the heat sources System B and System MB Obtura (Analityc Technology, Redmond, WA, USA). Thirty extracted human incisor teeth were used. Root canals were cleaned and shaped by means of Protaper rotary files (Dentsply-Maillefer, Belgium), and imaging was performed by micro-CT (Skyscan 1072, Aartselaar, Belgium).

METHODS

Teeth were instrumented with K-type thermocouples, and the roots were filled with thermoplastic gutta-percha. Vertical compaction was achieved through the heat sources System B and System MB, and temperature profiles were detect-ed by means of NI Dac Interface controlled by the LabView System. With both heat sources, higher temperature levels were recorded in the region of the root far from the apex. When the warm plugger tip was positioned at a distance of 3 mm from the root apex, temperature levels of about 180°C were used to soften gutta-percha, and no statistically significant differences were observed between peak temperatures developed by the two heating sources at the root apex. However, a temperature level higher than 40°C was maintained for a longer time with System MB.

RESULTS

Statistically significant differences were observed in peak temperature levels recorded far from the root apex. Thus, with a temperature of about 180°C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40°C at the apex of the root, suggesting that the gutta-percha was properly softened.

SIGNIFICANCE

A temperature level higher than 40°C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha.

Sealing Efficacy of Single-cone Obturation Technique with MTA and CEM Cement: An in Vitro Bacterial Leakage Study

Background and aims. Various materials and methods have been introduced for obturating cleaned and shaped root canal systems. This in vitro study aimed to evaluate the sealing ability of single-cone obturation technique with mineral trioxide aggregate and calcium-enriched mixture based on bacterial leakage approach.

Materials and methods. Sixty-four single-canal teeth were prepared and randomly divided into 5 groups, consisting of three experimental groups (n = 16) and two control groups (n = 8).In group 1, root canal obturation was performed using gutta-percha with 0.02 taper and AH26 sealer by lateral compaction technique. In groups 2 and 3, single Protaper gutta-percha cone was used for obturation with MTA and CEM cement, respectively. A bacterial leakage apparatus was utilized for leakage assessment for 60 days. Leakage comparison between the experimental groups was performed by one-way ANOVA using SPSS 16 statistical software.

Results. The mean bacterial leakage intervals in groups 1, 2 and 3 were 33.68 ± 9.39, 40.68 ± 11.03 and 39.56 ± 9.03 days, respectively. One-way ANOVA indicated no significant differences in bacterial leakage between the three experimen-tal groups (P = 0.109).

Conclusion. Single-cone obturation with well-fitted gutta-percha and MTA and CEM cement is an appropriate alternative for traditional lateral compaction technique.

The sealing ability of MTA apical plugs exposed to a phosphate-buffered saline

OBJECTIVE

The aim of this study was to evaluate the influence of exposure of the mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) - to phosphate-buffered saline (PBS) on the apical microleakage using a glucose leakage system.

MATERIAL AND METHODS

Sixty root segments were randomly divided into 4 experimental groups (n=15). After resecting the apical segments and enlarging the canals with Gates-Glidden drills, the apical cavities were filled with MTA with or without CaCl2 and the root canals were dressed with a moistened cotton pellet or PBS, as follows: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. All root segments were introduced in floral foams moistened with PBS. After 2 months, all root segments were prepared to evaluate the glucose leakage along the apical plugs. The amount of glucose leakage was measured following an enzymatic reaction and quantified by a spectrophotometer. Four roots were used as controls. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests (p<0.05).

RESULTS

There were no differences between groups 1 and 2 (p>0.05), and 3 and 4 (p>0.05). The addition of CaCl2 to the MTA significantly decreased its sealing ability (p<0.05).

CONCLUSION

The interaction with PBS did not improve the MTA sealing ability. The addition of CaCl2 to the MTA negatively influenced the apical seal.

Root-end filling with cement-based materials: An in vitro analysis of bacterial and dye microleakage

Background:

One ideal property of a root-end filling material is its apical sealing ability. The aim of this in vitro study was to assess bacterial and dye microleakage of white and gray mineral trioxide aggregate (WMTA and GMTA), Portland cement and calcium-enriched mixture (CEM) cement used as root-end filling material, and to assess the agreement between these two test methods.

Materials and Methods:

Fifty-four single-rooted teeth were used. The roots were randomly divided into four study and two control groups. After decoronation, root canals were instrumented and filled with gutta-percha and AH26 sealer. Root-ends were resected 3 mm above the root-end and 3 mm deep cavities were prepared. Root-end cavities were filled with each material. Enterococcus faecalis and methylene blue dye were used for determination of bacterial and dye leakage respectively. Data were analyzed using Fisher's Exact Test, one-way ANOVA, Kaplan-Meier analysis, and Cohen's Kappa.

Results:

There was 100% bacterial leakage in Portland cement and CEM cement, 58.3% in GMTA, and 91.7% in WMTA. GMTA showed significantly less bacterial leakage than Portland cement and CEM cement (P < 0.05). In those samples with leakage occurrence, times of observation of leakage were not significantly different; however, by survival analysis, the results of the GMTA group were significantly different from those of the CEM cement and Portland groups. The difference in complete dye leakage was not significant. There was poor agreement between dye and bacterial leakage methods.

Conclusion:

CEM cement provides leakage results comparable to other commonly used root-end filling materials such as WMTA.

Permanent molar pulpotomy with a new endodontic cement: A case series

The aim of this case series was to determine the clinical and radiographic success rate of pulpotomy, with new endodontic cement (NEC), in human mature permanent molar teeth. Twelve molars with established irreversible pulpitis were selected from patients 14 - 62 years old. The selection criteria included carious pulp exposure with a positive history of lingering pain. After isolation, caries removal, and pulp exposure, pulpotomy with NEC was performed and a permanent restoration was immediately placed. At the first recall (+1 day) no patients reported postoperative pain. One wisdom tooth had been extracted after two months because of failure in coronal restoration. Eleven patients were available for the second recall, with a mean time of 15.8 months. Clinical and radiographic examination revealed that all teeth were functional and free of signs and symptoms. Histological examination of the extracted teeth revealed complete dentin bridge formation and a normal pulp. Although the results favored the use of NEC, more studies with larger samples and a longer recall period were suggested, to justify the use of this novel material for treatment of irreversible pulpitis in human permanent molar teeth.

Sealing ability of MTA and amalgam in different root-end preparations and resection bevel angles: an in vitro evaluation using marginal dye leakage

This in vitro study evaluated the effect of different apicoectomy angles, instruments used in root-end preparation, and dental materials used in retrofilling on apical sealing. Root ends were resected at 45 or 90 degrees in 80 single-rooted teeth. For each type of apicoectomy, root-end cavities were prepared with either a round carbide #2 bur or an S12/90D ultrasonic tip. The root-end cavities in each subgroup (apicoectomy + root-end preparation) were filled with silver amalgam without zinc (Am) or with gray mineral trioxide aggregate -Angelus (MTA), and the specimens were immediately immersed in 0.2% rhodamine B for 24 h. Sealing was evaluated based on the dyed cross-sectional dentin area. Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. No group showed complete sealing of root-end areas. The only significant factor affecting microleakage was dental material, with MTA exhibiting less leakage.

Clinical study of Mineral Trioxide Aggregate in primary molars. Comparison between Grey and White MTA--a long term follow-up (84 months)

OBJECTIVES

The aim of the present study was to conduct a clinical and radiographic long-term evaluation of pulpotomy in temporary molars performed with Grey and White Mineral Trioxide Aggregate (MTA) and compare the results of Grey and White MTA pulpotomies in a sample of 233 primary molars with a maximum follow-up period of 84 months.

METHODS

The sample was selected from patients treated at the Department of Pediatric Dentistry, Faculty of Dentistry, Complutense University of Madrid, Spain. This prospective study included first and second primary molars treated with pulpotomy with Grey or White MTA, controlled for a maximum follow-up period of 84 months. Statistical analysis of clinical and radiographic findings was completed using ANOVA (P<0.05).

RESULTS

Follow-up evaluations, performed every 6 months, revealed that only 2 molars treated with White MTA presented abscess and pathological mobility. Radiographic examination of the 210 molars revealed unfavourable pulp response in only 6 molars (internal or furcation root resorption), without statistically significant differences between Grey and White MTA. Two radiological findings were noticed: dentine bridge formation and partial or total root canal stenosis. Grey MTA induced a higher percentage of dentine bridges with statistically significant differences (P<0.05), and a higher percentage of pulp canal stenosis, without a statistically significant difference.

CONCLUSIONS

Grey and White MTA presented high levels of clinical and radiographic success. Although the present study showed evidence of a very good biologic response with both types of MTA, Grey MTA showed significantly higher number of dentine bridge formation than White MTA.

Sealing ability, marginal adaptation and their correlation using three root-end filling materials as apical plugs

Objective

This study used dye leakage assay and scanning electron microscopy to evaluate, respectively, the sealing ability and marginal adaptation of three root-end filling materials used as apical plugs, as well as the possible correlation between these properties.

Material and Methods

Ninety-eight single-rooted human teeth were prepared to simulate an open apex. The teeth were allocated to three experimental groups (n = 30), which received a 5-mm thick apical plug of (1) gray MTA Angelus^TM, (2) CPM^TM and (3) MBPc, and two controls groups (n = 4). After immersion in 0.2% Rhodamine B solution for 48 h, the teeth were sectioned longitudinally and analyzed by Image Tool 3.0 software. The marginal adaptation between apical plugs and the root canal walls were analyzed by SEM.

Results

MBPc had significantly less (p<0.05) apical leakage than the other materials. Regarding marginal adaptation, CPM^TM showed the best numerical results, though without statistical significance from the other materials (p<0.05). There was no correlation between the two properties.

Conclusions

When used as apical plugs, the tested root-end filling materials had similar marginal adaptation to the dentin walls, but MBPc had the best sealing ability, as demonstrated by the least apical leakage from all tested materials.

A comparative histological analysis of human pulp following direct pulp capping with Propolis, mineral trioxide aggregate and Dycal

BACKGROUND

Permanent teeth pulp exposures have traditionally been treated with calcium hydroxide pulp capping. The aim of this study was to investigate the response of human pulp tissue which were mechanically exposed to a new material, Propolis and compare it with two existing and commonly used pulp capping agents (mineral trioxide aggregate and Dycal).

METHODS

Thirty-six intact human premolars were mechanically exposed. Teeth were divided into six groups of 6 teeth each and were capped with Propolis, mineral trioxide aggregate and Dycal. Final restoration was done with posterior composite resin using light cured glass ionomer cement as a liner. The teeth were then extracted on the 15th or the 45th day and processed for histological evaluation.

RESULTS

Differences in inflammatory response and dentine bridge formation of the exposed pulp to the three different materials were statistically calculated using chi-square test and were found to be non-significant. There was more pulp inflammation in teeth treated with Dycal than with Propolis and MTA on the 15th as well as on the 45th day. Propolis and MTA showed bridge formation in more teeth, and the bridges were in closer proximity to pulp capping material than teeth treated with Dycal on the 45th day.

CONCLUSIONS

The response of pulps to Propolis as a pulp capping agent was comparable to MTA and Dycal.

In vitro comparison of three materials as apical sealants of equine premolar and molar teeth

REASONS FOR PERFORMING STUDY

Surgical endodontic therapy is a conservative dental technique used in horses with some degree of clinical success. Failure of this procedure can partially be explained by inadequate sealing of the root apices with resultant microleakage in the periapical area.

OBJECTIVES

To assess and compare in vitro sealing ability of 3 different dental restorative materials used as apical sealants during equine surgical endodontics.

METHODS

Thirty extracted equine cheek teeth were divided randomly into 3 groups and subjected to apicoectomy and apical sealing using 3 materials: reinforced zinc oxide-eugenol cement; intermediate restorative material (IRM); a resin-modified glass ionomer; and amalgam. After apical sealing, the teeth were submerged in a solution of Procion Brilliant Cresyl Blue stain for a period of 7 days. The teeth were then washed, embedded in resin, sectioned and assessed microscopically for dye leakage around the apical restorations.

RESULTS

Although the materials proved effective as apical sealants, some dye leakage was encountered in all 3 groups with no statistical difference (P = 0.114).

CONCLUSIONS AND POTENTIAL RELEVANCE

IRM, a resin-modified glass ionomer and amalgam all showed comparative features as apical sealants when used in vitro in equine teeth. IRM is currently regarded as the superior material in clinical situations due to its ease of handling and lesser sensitivity to environmental moisture during placement compared to the other 2 materials.

Periapical surgery using ultrasonic preparation and thermoplasticized gutta-percha with AH Plus sealer or IRM as retrograde root-end fillings in 160 consecutive teeth: a prospective randomized clinical study

OBJECTIVE

The aim of this study was to evaluate the healing outcome after periapical surgery with an ultrasonic cleaning technique in conjunction with the use of either of 2 different retrograde root-filling materials in teeth with apical periodontitis.

STUDY DESIGN

One hundred sixty teeth in 139 consecutive patients were randomly allocated into 2 groups receiving either IRM or thermoplasticized gutta-percha (GP) with AH Plus sealer as a retrograde root-end seal. The patients were reviewed 12 months after surgery. The results were analyzed with Fisher exact test.

RESULTS

One hundred forty-seven teeth in 131 patients were reviewed. Radiologic evaluation and clinical examination showed an 85% success rate for the IRM group and 90% for GP group. There was no statistical significance between the 2 groups.

CONCLUSION

Both tested materials, IRM and GP, are suitable as retrograde root-end filling materials in conjunction with ultrasonic root-end preparation according to the results of the healing outcome after 12 months follow-up.

Radiopacity evaluation of root-end filling materials by digitization of images

The purpose of this study was to evaluate the radiopacity of 5 root-end filling materials (white MTA-Angelus, grey MTA-Angelus, IRM, Super EBA and Sealer 26). Five specimens (10 mm diameter X 1 mm thickness) were made from each material and radiographed next to an aluminum stepwedge varying in thickness from 2 to 16 mm. Radiographs were digitized and the radiopacity of the materials was compared to that of the aluminum stepwedge using VIXWIN 2000 software in millimeters of aluminum (mm Al). Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. Radiopacity values varied from 3 mm Al to 5.9 mm Al. Sealer 26 and IRM presented the highest radiopacity values (p<0.05), while white/grey MTA and Super EBA presented the lowest radiopacity values (p<0.05). The tested root-end filling materials presented different radiopacities, white/grey MTA and Super EBA being the least radiopaque materials.

A comparative study of histologic response to different pulp capping materials and a novel endodontic cement

OBJECTIVE

The aim of this study was to compare dogs' pulp response to capping with calcium hydroxide cement (Dycal), mineral trioxide aggregate (MTA), and a novel endodontic cement (NEC).

STUDY DESIGN

Twenty-four canine teeth in 6 beagle dogs were buccocervically exposed and capped with MTA, Dycal, or NEC. Eight weeks later, retrieved samples were observed by optical microscope to grade inflammation, formation of dentinal bridge, calcification, necrosis, and presence of odontoblast cells.

RESULTS

No inflammation was observed in MTA and NEC groups, and in 75% of each, dentinal bridge was completely formed. In the Dycal group, inflammation and incomplete dentinal bridge were detected in all cases. Although MTA and NEC groups had no significant difference between them in each measure, the difference between all 3 groups was significant (P < .001).

CONCLUSION

MTA and NEC showed similar favorable biologic response in pulp cap treatment, better than Dycal, especially in inducing the formation of dentinal bridge.